chapman



i 4 Sheets-Sheet I.r W.'1E[AP1V1AN DIFFERENTIAL PULLEY- l (No Model.)

Patented Deo. 26, 1893. l

(No Model.) 4 Sheets- Sheet 2'.

W. CHAPMAN.

- DIFFERENTIAL PULLEY. No. 511,505. Patented Defc. 26, 1893.

NQLCXGL y NITED YSTATES PATENT OFFICE.

WILLIAM CHAPMAN, OFy WASHINGTON, DISTRICT OF COLUMBIA.v

DIFFERENTIAL PU .LEY.

SPECIFICATION forming partof Letters Patent N o. 511,505, dated December 26, 1893.,

Application filed March 8, 18-93. SerialNo. l65,121. @To model.)

To all vwhom it may concern:

Il e it known that I, WILLIAM CHAPMAN, a cltizen of the United States, residing at Washington, in the District of Columbia, havel inyented certain new and useful Improvements 1n Pulley-Blocks, of which the following is a specification.

My invention relates to that class of pulley blocks in which motion is transmitted from a hand-chain pulley to a lifting chain pulley through intermediate gearing, and the improvenients consists in certain features, details and combinations hereinafter set forth, but pertaining more particularly to means for holding the loadv in its elevated position or controlling its descent, as required.

In the accompanying drawings,-Figure l is aside or face elevation (of the device comdrawings, in whichplete. Fig. 2 is a vertical section on th'e line w-- of Fig. 1; Fig. 3, a partly sectional perspective view, showing the parts separated; and Figs. 4 to l2 inclusive, detail views of parts, hereinafter referred to.

The purpose of my invention is to produce a simple, cheap and efficient differential pulley block,'which shall afford adequate power, and give perfect control over the load, both 1n raising and lowering the same. To this end I adopt the construction shown inthe A indicates a suitable frame orY bail, advisably of metal, and provided with the customary swiveled suspending hook B. A

N earthe lower end of the bail or frame A is a horizontal pinl or bolt C, which constitutes the axle of a combined gear and chain wheel D, E, the gear wheel D being internally-toothed, and the chain wheel E having the customary link seats or sprockets to receive or engage the load chain F.l The chain F may be of any approved pattern, single or double, and may carry merely a hook G, orv Y hub or sleeve fn, .which closely tits upon and may have one end made fas-t to the bail or frame A, and a running block carried in the loop or f'old of the chain, as is commonv and well understood.

Motion is imparted to the combined gear-V The spindle or arborI .passes'axiallythroughl arbor I, as indicatedv'in fFig. 2.

a tubular sleeve J, which is nicely fitted within a tubular neck K of frame or bail A. The sleeve J is formed with a'radial flange a at one end, land has screwed or otherwise made fast upon its other end a collar L, comprising a cylindrical boss b, and a conical neck c, which latter is turned true, and'fits a cor- -responding seat in the tubular neck K of the frame or bail A. To preventthe collar L from vworking loose, it is advisable to key or pin it, as indicated.

M indicates a lever, pivotallysupported upon the rsleeve J, at a point between the iiange ctof said sleeve, and the end of the tubu v lar neck K,`as shown in Figs. 2 and 3, a washer d, of leather orv other suitable material being zontal position, to which it is carried and-in which itis heldby a counterweight'g, they shall act to throw the lever outward or toward iiange ya of sleeve J. This. outward pressure being transmitted .to the flange and consequentlyto the 'sleeve J, moves the latter longitudinally, and draws the conical neck c of collar L firmly into its seat, thereby producing frictior suflicient to preclude the turningof the sleeve or collar, even under convadvisably interposed between the side face of siderable force tending to'that end. There may of course be eithera single incline, or a series thereof on the opposing faces of the lever and ring or 'collar N, two being shown in the drawings. Y

Of indicates a disk, formed with a tubular is' keyed or'otherwise made fast to spindle or The disk O carries on its face to'ward the frame or bail A, a series of eccentric pawls '1),` which are. conevenientlyv formed with cylindrical.' pivotal ribs g to restin semicircularseats or bearings in posts h, projecting from'the face of the'` disk, as best shown in Fig. V.' i( f The pawls arelimited in their play or movements by projecting studs i, working in slots `7 in the disk O, concentric with the pivots of the pawls, and each pawl is pressed lightly inward or toward the collar L, by a spring k, one end of which is made fast in a stud or post Z, projecting from the face of disk O.

Q indicates a hand chain wheel, loosely mounted and free to turn a limited distance io upon and independently of the sleeve n, of disk O, the extent of play being determined by the spacing of interlocking lugs o and p,

projecting from the face of the'disk and theV face of the hand-chain wheel respectively.

i 5 The hand-chain wheel is further provided"m with a series of arms q, projecting from the same face as the lugs p, and curved on one face,.as shown in Figs. 3, Il, 5 and 9. Under a certain relative adjustment of the disk and zo the haiid-chain wheel hereinafter explained,

the. outer extremities of the arms q ride beneath the studs t' of pawls P, which studs project through and beyond the disk as shown in Fig. -2,-and lift said pawls out of contact z 5 with collar L. The usual endlesshand-chain R passes over wheel Q, and a rope S, a chain, or other Iiexible band is att-ached to and hangs down from the end of lever M opposite that `whichcarries the counterweight. t

The device being thus constructed, its operation is as follows: The load is made fast to the hoisting chain F in any convenient way, and the hand-chain is then drawn down to the right. by caused to rotate upon the sleeve n, until the lugs p of said wheel come into contact with the lugs o of the disk O, whereupon the disk O, and consequently the spindle I and pinion H rotate with the wheel Q, and` the 4o pinion turns `the combined gear and'chain wlieelD, E, thereby elevating the load. During the upward movement of the load, the pawlsP,.resting upon the cylindrical boss b of the collar L, `which is norinallyiheld against rotation, as. explained, t ride freely over Athe face `of saidcollanthe slight friction tending to` swing them outward and to bringthat por-` tion of the` face of each having the shortest radius against the` boss b, so that theypro: 5c duce noretardingfetfect. If the, strain` or force applied to the handchain be removed, however, the weight of the load immediately operates to turn the parts backward, butthe moment suchfbackward rotation begins, and before it becomes appreciable, the pawls P bearingupon the collar L, bind thereon by reason of `their movement being in the direction of their increasing radius.` A very slight swing of the pawls in this `direction causes 6o them to lockn the disk` O firmly to the collar, andprevent rotation of the disk and the parts controlled. thereby., i To lower the load it is onlyhecessary to drawdown upon the rope or i chain S, therebyturning the cam face or 6'5 incline c of lever M backward upon orrelatively to the opposing cam face or incline f,- thereby permitting suicient longitudinal The hand-chain wheel `Q is there` movementot sleeve J to free the conical 'neck c of collar L in its seat. This permits the sleeve and collar to turn in the neck K of` frame A, under the weight of the load transmitted through the gear wheel and pinion, the spindle or arbor, the disk and the pawls. The friction may be diminished as little or'as much as may be desired, by carefully 1nanip ulating' the lever M, through rope S,-the full friction and rigid locking of the sleeve and collar occurring immediately upon vrelease of the rope, by reason of the action of the counterweight. WVhen the load requires to be lowered with more than ordinary care, or to be lowered accurately toacertain point, or whenlt is desired to lower the nnladen hook, the handwheelchain is drawn down onthe left hand side, causing `the rotation of wheelQ inthe direction indicatedby arrow in Fig. 5w When the wheel Q isthns rotatedand just before or at the instant that the lugs pcomeintoy `contact with the lugs oy ofdisk `O, the outer `extremities of the curved arms@` of wheel `ride beneath the studs i of pawls P, and ulift said pawls4 out of` contact wfthlhe cplluarL.

The backward, rotationioflivi'heel Q and, `disk 10, with their connected partsinaytherefore be continued indefinitely withoutliinderance; butif the handfchain wheel Q be turned again Slightly forward, the arms Q` willw .fida frpm beneath the pawls `and leave them free to go into action the ii'istanttliey are `required to do so. During the operation of loweringby the hand chain the load causes the diskvand its pawls to follovt1 closely the niovementsof `the handwheel and tomlock the instant the hand chain is released. It is apparent that ,the number .of t Lugge p, the number of pawls, ,the` inannerofwipivoting or mounting `the latter, theconfiguraj tion of theseveral friction surfaces, andpther ,i 1,1. J ,1.1 l my invention, what details may be varied without departing from j IIO meshing with said gear wheel; a spindlegearrying said pinion and.. providedwith ad k a rotatable sleeveencircling -theuspindli ,and

mounted-,in the bail or frame; lpawlscarried by the dskidapted. mangas@ `it.litlltlnifileset@ t and "prevent backward Arotation,oljf the` `disk and spindle; a hand-chainiwlieeladaptedtto engage with and rotate the Ldisk; ,andaweightf ed cam lever, serving to move `the, sleeve 1on1 gitudinally and to hold it nOliliallyin frictional engagement ,with thebail or frame.

2. In combination withbail orframer hayf iugctubular neck K; Sleen@ J mtiuntednd adapted torotate in said-neck, and provided with flange at` andcollar b; spindlel `passing through sleeve J and provided with pinion H and slotted disk O 5 pawls P carried by disk O,

provided with studs z', and arranged to engage with collar b; hand-chain wheel Q, provided with arms q and withvlugs to engage with similar lugs of disk O; .combined gear and chain Wheel D, E, the gear D meshing with pinion I-I; and weighted. lever M provided with incline'e and serving to draw the sleeve J into firm frictional contact with its seat,- substantially as set forth.

3. In a pulley block or hoisting device of the class described, the combination with the hoisting mechanism proper, of a locking and releasing device, comprising a sleeve capable of rotation within the main frame, pawls carried by the hoisting mechanism and adapted to lock upon said sleeve, and a weighted cam lever normally acting to draw the sleeve firmly to its seat in the main frame and hol it against rotation. Y

4. In combination with the differential gearing of a pulley block or hoisting device such as described, the lookin g and releasing device comprising sleeve J provided with ange a, collar b, and conical neckc; lever M provided with incline e acting between the main frame or bail and the flange ci; and pawls P carried by the hoisting mechanism proper, and adapt-y ed to engage with collar b to prevent backward rotation of said hoisting mechanism.

5. In a pulley block or hoisting device of the class described, the combination with hoisting gear provided with lockingvpawls, of a sleeve for the pawls to engage with, rotatable in the main frame of the device and adapted to be made fast to or released from the frame by longitudinal movement, and a lever adapted and arranged to eect longitudinal movement of said sleeve in either Adirection, at the will of the operator.

6. In a pulley block or hoisting device, the combination of hoisting gear a rotatable sleeve independent thereof means for locking and releasing the same at will, a slotted disk carl ried by a member of the hoisting mechanism proper, provided with pawls to lock upon the sleeve; springs acting upon said pawls to throw them into engagement with the sleeve,

ing device, encircling said arbor' and independent 4of the hoisting pulleys sleeve J and means for locking and releasing saidsleeve at will,-a series of pawls P carried by a disk t),y

vent backward rotation of the spindle,'except in unison with the sleeve. I v

8. In a pulley block or hoisting device, the combination of a rotatable sleeve, a pressure lever acting upon said ,sleeve to `hold it in frictional engagement with the frameof the device; hoisting gear; and pawls carried by said gear and adapted to engage with th'e sleeve the instant said gear begins to turn backward. 9. In a pulley block or hoisting device, lthe combination with hoisting gearprovided wlth locking pawls; and with a rotatable sleevefor the pawls to engage with; a lever M bearing.

secured upon said spindle, said pawls being adapted to engage with the sleeve and preon one .face against the sleeve and having on the otherV face an incline bearing against. a

projection on the main frame of the device;'

`whereby the rocking of the lever is caused to hold the sleeve against rotation or to release the lever is moved. v l

In witness whereot` I hereunto set my hand in the presence of two witnesses. l

WILLIAM CHAPMAN. Witnesses:

HORACE A. DODGE, WALTER S. DODGE.' 

